BCS Superconductivity of Dirac Electrons in Graphene Layers
Abstract
Possible superconductivity of electrons with the Dirac spectrum is analyzed using the BCS model. We calculate the critical temperature, the superconducting energy gap, and the supercurrent as functions of the doping level and of the pairing interaction strength. Zero doping is characterized by the existence of a quantum critical point such that the critical temperature vanishes below some finite value of the interaction strength. However, the critical temperature remains finite for any nonzero electron or hole doping level when the Fermi energy is shifted away from the Dirac point. As distinct from usual superconductors, the supercurrent density is not proportional to the number of electrons but is strongly decreased due to the presence of the Dirac point.
 Publication:

Physical Review Letters
 Pub Date:
 June 2008
 DOI:
 10.1103/PhysRevLett.100.246808
 arXiv:
 arXiv:0803.3772
 Bibcode:
 2008PhRvL.100x6808K
 Keywords:

 73.63.b;
 74.25.Jb;
 74.78.Na;
 Electronic transport in nanoscale materials and structures;
 Electronic structure;
 Mesoscopic and nanoscale systems;
 Condensed Matter  Superconductivity;
 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 Phys. Rev. Lett. 100, 246808 (2008)